This latest recounting of the 1799 discovery of the Rosetta Stone—the key to deciphering ancient Egyptian hieroglyphics—focuses less on the decoding itself and more on the French invasion of Egypt that led to the discovery and the military and cultural battle with Britain that followed. British military historian Downs tells an engrossing story full of larger-than-life and sometimes simply wacky characters, led to Egypt by Napoleon. Among them were dozens of scholars, artists and scientists who produced an explosion of knowledge on both ancient Egyptian and later Islamic culture. The invasion itself ended in disaster when Admiral Nelson's armada destroyed the French fleet at the Battle of the Nile. Napoleon returned to France; his army, left to wither from heat, disease and deprivation, surrendered to Britain in 1801. Much of the book concerns clumsy French efforts to avoid turning over their artifacts, including the Rosetta stone, to the victors. Downs takes an original tack to this well-known story with a straightforward, dramatic account of the 1,500-pound stone from its discovery until its arrival at the British Museum, where it rests today. (July)